For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningRemoval Procedure
Warning: Refer to Glass and Sheet Metal Handling Warning in the
Preface section.
Disable the SIR System. Refer to SIR
Disabling and Enabling.
Disconnect the negative battery cable. Refer to Battery Negative Cable
Disconnection and Connection.
Remove the rear side door. Refer t ...
Additional links
Instrument Cluster Replacement
Preliminary Procedure
Remove instrument panel lower cluster trim plate. Refer to Instrument
Panel Cluster Lower Trim Plate Replacement.
Remove instrument panel steering column upper trim cover. Refer to
Steering Column Upper Trim Cover Replacement.
...
Installation Procedure
Create 5 x 18 mm (4/16 x 11/16 in) slots for MIG-brazing along the edges
of the tail lamp pocket as noted f rom the
original panel.
Note:
Clean and prepare the attaching surfaces for brazing.
Position the tail lamp pocket on the vehicle.
Verify the fit of the ta ...